1. Field of the Invention
The present invention relates to an electronic musical instrument with a touch response function, which reflects the touch response such as key-depressing speed or string picking force of operating means such as keys or strings, onto musical tones.
2. Description of the Related Art
Conventionally, there are electronic musical instruments which produce musical tone waveforms from a plurality of tone waveform generators, synthesize these waveforms and generate a musical tone having the synthesized waveform, thus providing musical tones with depth for ensemble effects. CZ-1, a Casio product, is an example of such instruments. This type of electronic musical instruments have some problems. The first problem is that there is not sufficient variation in a musical tone due to the use of only one type of a touch response waveform data (herein after referred to as touch curve) in all the tone generators in modulating individual tone waveforms from the mentioned tone waveform generators based on touch curves having parameters such as a key depressing speed in order to reflect the key depressing speed etc. on musical tones These touch curves increase with an increase in, for example, key depressing speed.
The second problem is that the aforementioned product, CZ-1, corrects or changes the values of a touch curve to attain a new touch curve by simply performing addition, subtraction, multiplication and division of the same correction value on all the values of the old touch curve. That is, the pattern of the touch curve itself does not vary. Naturally, this cannot provide a large variation in musical tones.